Amersham pursues new uses for Ceretec

Amersham International has entered a licensing agreement withBristol-Myers Squibb and Oxford University, U.K., that could resultin the use of Amersham's Ceretec radiopharmaceutical brain imagingagent for the detection of Alzheimer's disease. Amersham's U.S.subsidiary, Medi-Physics of Arlington Heights, IL, plans to filean application with the Food and Drug Administration that wouldadd the differentiation of Alzheimer's disease to Ceretec's listof approved indications.

Medi-Physics said last month that a study of 300 patients conductedby Oxford researchers, in cooperation with Bristol-Myers Squibb,revealed that Ceretec can be used for differentiating betweenvarious forms of dementia. When combined with anatomical imagingsuch as CT, SPECT studies with Ceretec yielded a sensitivity ratefor Alzheimer's of 90% and a specificity rate of over 95%.

The diagnosis of Alzheimer's disease is difficult and can beconfirmed only by postmortem microscopic examination of braintissue, according to Amersham. Other tests lack both sensitivityand specificity, the company said.

If Ceretec does prove useful in diagnosing Alzheimer's, itcould have a major impact on patient management, particularlyin the development of new drugs to treat the disease, accordingto William Ehmig, vice president for professional affairs at Medi-Physics.

"There are a lot of drugs in phase I and phase II trialsthat, if you had some way to stage the patient, you could tellbetter if the drug was working in the early stages of trials,"Ehmig said. "If you can detect the disease early and startearly treatment, it might delay the onset."

Ehmig believes that Medi-Physics will be able to file a supplementto Ceretec's new drug application by the end of the summer. FDAofficials have indicated that they would consider an expeditedreview of the application based on data from the Oxford study.